http://localhost:8081/jspui/handle/123456789/25 Wed, 21 Oct 2026 22:24:01 GMT 2026-10-21T22:24:01Z http://localhost:8081/jspui/handle/123456789/21749 Title: Development of a Performance Evaluation Framework for Public Transport Systems Authors: Verma, Vishwajeet Kishore Abstract: Public transport is an important component of a transportation infrastructure and is a sustainable transport solution. It has evolved over the centuries from animal back and animal drawn systems to motor driven system of today. The development has been phenomenal regarding passenger handling capacity, the speed of operations, and system efficiency. It provides economic travel, utilizes fuel efficiently, produces higher passenger-kilometre per unit time, and needs low unit space per passenger for its facilities. Focused efforts have been made by several international organizations to improve transit systems in their respective jurisdictions. Despite these efforts, the public transport modal shares are either going down or remaining stagnant in several countries including India. This is due to the inherent characteristics of the public transport system and the changes in the aspirations of the commuters over time. Research across the globe has observed several possible reasons for the decrease in the transit modal shares. These have consequential impacts on declining ridership. The declining patronage of sustainable transportation like public transport is a worrying factor and needs assessment to arrive at remedial measures. Sun, 01 Dec 2024 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/21749 2024-12-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/20954 Title: RAP MATERIALS FOR SUSTAINABLE PAVEMENT QUALITY CONCRETE Authors: Abraham, Sarah Mariam Abstract: Utilisation of Reclaimed Asphalt Pavement (RAP) aggregates in rigid pavement mix has been gaining momentum but confined to laboratory level of research with few field applications. Past research suggests that RAP aggregates has the potential to be an alternative to natural aggregates which could suppress the pressure of dumping of the same on landfills and resolve the issue of depletion of virgin aggregates. Recycling of RAP aggregates back in bituminous mixes has been well established with published specifications for the design such as IRC:120 (2015). But it is recommended to utilise RAP aggregates which are retrieved from flexible pavements of younger age (age of 5 to 10 years) with higher bitumen content than older pavements with lower bitumen content and subjected to oxidation due to stockpiling, since the former would reduce the amount of fresh bitumen to be added. The RAP aggregates that are retrieved from older pavements is beneficial in recycling to rigid pavement mix. Therefore, the recycling of RAP aggregates can go hand - in - hand between flexible and rigid pavements. In case of utilisation of RAP aggregates in cement concrete mixes, the focus has been given to the coarse fraction of RAP aggregates with limited literature on fine fraction. Hence the scope of the study lies on analysing the feasibility of utilising fine fraction of RAP aggregates as partial or complete alternative to natural fine aggregates in pavement quality concrete mixtures, based on their performance with respect to strength, durability and permeation characteristics. By doing so, the observation and analysis can be added to the limited literature and could be a step forward in preparing standard specifications for recycling of RAP in rigid pavements. To achieve the objectives step – by- step procedure is adopted. Initially, the fine fraction of RAP aggregates and natural fine aggregates were assessed for comparative study where it was observed that even though the parent rock is the same between them the specific gravities are different, the former being lower than the latter. The fine RAP was coarser in particle size distribution and darker in colour with layer of dust upon the asphalt film on the aggregate which could not be removed even after washing. In order to analyse the sole effect of fine fraction of RAP aggregates without the blinding effect of natural coarse aggregates, cement mortar samples were prepared with 25,50, 75 and 100% replacement of natural fine aggregates. By analysing the effect of gradation and mode of replacement (weight and volume replacement) upon strength parameters it was observed that gradation does have statistically significant effect on strength parameters. It is recommended to adopt volume replacement methodology rather than weight replacement technique since the latter fails to address the variation in specific gravities between the types of aggregates, producing samples with unequal volumetric content and resulting in unstandardized comparison. Even though with the incorporation of RAP aggregates in mortar mixes resulted in reduction strength parameters, mixes with 25% and 50% of RAP aggregates were able to achieve 28-day characteristic compressive strength needed for Ordinary Portland Cement (OPC) Grade 43. It was also observed that flexural strength of RAP mortars had undergone lower reduction than compressive strength which was noteworthy. Addition of mineral admixtures namely silica fume and activated sugarcane bagasse ash as partial replacement of cement improved the strength parameters and moreover had a significant impact on reduction in drying shrinkage, even being at par with conventional mixes. With the addition of mineral admixtures, even 75% replacement of fine aggregates was possible while meeting the stipulated strength requirements. Interesting behaviour was observed for resistance against sulphate attack for RAP inclusive cement mortars where gain of strength was obtained for 25% and 50% replacement mixes even after 90 days of sulphate attack. The behaviour was replicated by mortar mixes with mineral admixtures at the same RAP replacement level. The gain as well as loss in strength due to sulphate attack was substantiated using pore structure characteristics obtained by Mercury Intrusion Porosimetry (MIP) and the delay in formation and filling of salt – crystallization products in pores of the samples. Porosity determined through MIP increases with RAP content and existing strength – porosity models holds good. A pragmatic approach was adopted when concrete mixes were prepared with RAP aggregates. The requirement of slump of 25±10mm was given priority than maintaining a constant water – to – cement ratio. Concrete mixes included the mixes with 25,50, 75 and 100% RAP content as well as the optimal mineral admixture mixes corresponding to each replacement level. Flexural strength is a primary factor for the design of rigid pavements. RAP inclusive concrete mixes with 25,50 and 75% RAP content and their corresponding mineral admixture mixes were able to attain the target flexural strength of 4.85MPa with a maximum reduction of 9.7% when compared to conventional mix. RAP inclusive concrete mixes possess the character of increased rate of development of strength than conventional mixes. The RAP concrete mixes did not facilitate to corrosion due to absence of carbonation, maintenance of alkaline pH of 12-13 and the chloride content was within the stipulated limits. At the same time from presence of entrained air bubbles observed from MIP analyses showed the qualitative ability of RAP mortars and concrete to protect the cement paste from frost damage and salt decay. Fractal dimensional analysis was used to describe the pore – solid structure of RAP inclusive cement mortars and concrete. Multifractal dimensions were displayed by the mixes and pore – mass fractal dimension was able to describe the pore – solid structure. These characteristics shows the potential of RAP aggregates to act as an alternative to natural aggregates for rigid pavements. Performance evaluation of optimal mixes of RAP concrete was assessed using pavement prototype analysis where the variation of temperature with respect to depth and corresponding stresses developed for pavement quality concrete section were assessed. From the analysis that was conducted for a duration of 365 days, it was observed that the temperature profile was non – linear in nature and was truly linear only for less than 1%. The RAP inclusive prototype exhibited lowest value of maximum positive (78.57% reduction) and negative (2.04% reduction) temperature differential and also exhibited reduced total temperature stress in comparison to conventional mix. The assumption of linear temperature profile failed to identify the nature of stresses (compressive or tensile) at most 50% of cases. Hence it is recommended to at least consider the non – linearity nature of temperature profile and amend the design codes pertaining to temperature profile and stresses where blind assumption of linearity shall not be taken. Wed, 01 Jul 2020 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/20954 2020-07-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/20527 Title: STABILITY OF RESERVOIR RIM SLOPES SUBJECTED TO FLUCTUATING WATER LEVEL Authors: Chandel, Anoopsingh Jainarayansingh Abstract: Existence of the reservoir-induced landslides has been acknowledged worldwide as a major barrier in the effective and successful functioning of hydro-power projects. Events of reservoir induced landslides have simultaneously risen in the past few decades along with the increase in number of hydro-power projects. Reservoir-induced landslides are more complex in nature than the landslides observed in mountainous regions as there can be several causes of failure. The triggering factors for the reservoir-induced landslides are mainly seepage, rainfall, geometric instabilities, and reservoir-water level fluctuations. Reservoir-induced landslides are often linked to fluctuations in reservoir water levels. For instance, more than 5000 landslides have been witnessed in Three Gorges Reservoir (TGR) since the commissioning of the TGR Dam, majority of which have been attributed to water level fluctuations. There exist various theories that explain the failure mechanisms of these landslides due to such fluctuations. Still, the failure mechanism of reservoir-induced landslides due to water level fluctuations is not clearly understood. Besides, limited studies are available on the displacement prediction models for rim slopes experiencing movements implicitly due to reservoir level fluctuations. The available prediction models are based on long-term in-situ field displacement monitoring. A detailed investigation is essential to understand the various aspects of the failure mechanism of these fluctuations-induced landslides. The contribution of reservoir water level fluctuations as an isolated triggering factor needs to be quantified. With the increasing number of hydro-power projects in India as well as throughout the globe, a simple quick assessment tool for predicting rim slope displacements based on easily available field slope data is the need of the hour. The present study aims at exploring the failure mechanism of rim slopes specifically due to reservoir water level fluctuations, and to come up with a simple generalized empirical solution to predict the displacements along the field rim slopes based on available field data. To achieve the objectives of the present study, an extensive experimental program was planned followed by seepage and stability analyses of the test results. A small-scale physical slope model test (PSMT) apparatus was developed indigenously to study the rim slopes subjected to fluctuating water levels. Eight PSMTs were performed in total. Two PSMTs were performed in steady-state condition to study the initiation and propagation of rim slope failures in steady-state seepage i condition with varying soil type (c-ϕ soil from Koteshwar, and sandy soil from Solani river) and slope inclination (30° and 45°). Six PSMTs were performed on a modelled soil (i.e. scale-reduced soil derived from a rim slope site in Koteshwar reservoir using parallel gradation technique) subjected to reservoir water level fluctuations. The six PSMTs were performed by varying cyclic fluctuation rate (i.e. 16 cm per 6 hours – slow, 16 cm per 1 hour – moderate, and 16 cm per 10 minutes - rapid), slope inclination (30° and 45°), and number of cycles (i.e. up to 30 cycles). During the experimentation, total head values with the help of piezometers installed on the setup, degradation of slope face, and deformed slope profiles with the help of deformation gauge, were observed at different test stages. The observations were made until the model slope failure occurred in steady-state condition, and up to the completion of 30 cycles when subjected to reservoir fluctuations. Lastly, seepage and stability analyses of the PSMTs results were performed to gain deeper understanding about the failure mechanism. The results and analyses of PSMTs in steady-state condition revealed that the cause for initial failures in the case of slopes that are reasonably stable under steady-state seepage condition is highly likely due to high exit hydraulic gradient. The initial slope failure will be induced within the region of high hydraulic gradients. The depth of failure surface will mostly be governed by the soil type. As the soil changes from cohesionless soil to a cohesive soil, the depth of failure slip surface tends to be increasing with cohesion being mobilized. There is a high probability of retrogressive failure phenomenon in the case of cohesionless granular soils. Using the experimental observations of PSMTs subjected to cyclic fluctuations, the analyses of PSMT observations were carried out in various ways. Firstly, spread (displacement at toe) was assessed. It was found that the amount of spread is high for slopes subjected to slow cyclic fluctuations in comparison to slopes subjected to rapid cyclic fluctuations. Change in pore water pressure just after the drawdown with successive cycles were studied for the performed PSMTs. The results suggest that sharp accumulation of pore pressure occurs during the initial cycles of water level fluctuation. The rate of increase in pore pressure decreases afterwards, and stabilizes for the remaining cycles of water level fluctuations. Seepage analysis was carried out to validate the trend of total head values observed during experimentation for reservoir water level fluctuations. The pore-pressure derived from the seepage analyses were then used for stability analysis. It was found that the stability of slopes subjected to cyclic fluctuation strongly follows the water level fluctuation scheme. Lastly, volumetric evolution, and static liquefaction ii were evaluated. Static liquefaction assessment concluded that the rim slopes are susceptible to static liquefaction under the influence of cyclic fluctuations. Based on the test observations, deformational behavior of rim slopes subjected to cyclic fluctuations was suggested. It was elicited that deformations and pore-pressure are inter-related to each other. Deformations occur mostly due to the high excess pore pressure generated after drawdown of each cycle. The rate of deformation reduces during the impounding process. Permanent deformations get accumulated with every passing cycle. Initial cycles of water level fluctuations cause large deformations at a high rate with the possibility of shallow toe failure during the initial cycle drawdowns. The rate of deformation reduces over passage of successive cycles. However, repeated cyclic fluctuations induce weakening effect in the slope mass (strain softening phenomenon). Spread observed from the PSMTs was then used to propose a novel approach to predict displacements along rim slopes due to reservoir water level fluctuations. A dimensionless term called Spread Index (Silab) was defined. The index was defined as the ratio of Spread (horizontal displacement at toe) and Hydro-Fluctuation Belt (HFB) of the cyclic fluctuation in the reservoir water level. Spread index was obtained for all the tests subjected to 30 cycles. Spread index data were used to perform multiple linear regression analysis. The spread index (Silab) was considered to be dependent on slope inclination (θsm), cyclic fluctuation rate (CFR) and number of cycles (Nc). The obtained regression equation was then statistically examined for goodness of fit, multicollinearity among the parameters, hypothesis testing by ANOVA. A correction factor Ci, field was defined to account for the influence of change in the ratio of hydro-fluctuation belt and slope height. Finally, an empirical solution to compute the spread in the field was suggested. The proposed empirical solution was validated by assessing the displacement for three landslide sites. The predicted displacements were compared with the already observed displacements in the field. An error of approximately 10% was observed. Lastly, the proposed empirical solution was used to predict displacements along a rim slope situated in Koteshwar reservoir, India. Sat, 01 Jun 2024 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/20527 2024-06-01T00:00:00Z http://localhost:8081/jspui/handle/123456789/20485 Title: UAV FOR HILLY AREA MAPPING AND OBJECT DETECTION Authors: Singh, Chandra Has Abstract: In recent years, Unmanned Aerial Vehicles (UAVs), colloquially referred to as drones, have instigated a paradigm shift across diverse industries by delivering unparalleled proficiency in data acquisition, analysis, and surveillance. Among the myriad applications, their role in hilly area mapping and object detection stands out as particularly promising and impactful. The intricate topography and varied landscapes of hilly regions present unique obstacles for conventional mapping methodologies, positioning UAV technology as an indispensable instrument for efficient and precise data procurement. This exposition endeavors to comprehensively elucidate UAV utilization for mapping and object detection in hilly areas, delineating the significance of this technology, elucidating the challenges endemic to traditional methods, and illustrating the transformative influence of UAVs in overcoming these obstacles. Hilly terrains engender a plethora of challenges for conventional mapping techniques. Traditional surveying methods, such as ground-based or manned aerial surveys, are frequently impracticable or economically prohibitive in such rugged environments. Protracted durations, and labor intensive procedures characterize these methodologies and often fail to furnish the requisite level of granularity necessary for precise mapping and object detection in hilly regions. Traditional mapping methodologies confront several inherent limitations when applied to hilly terrain. Primarily, the rugged topography and precipitous inclines render ground-based surveys arduous and perilous for surveyors. Accessing remote or inaccessible regions poses an immense challenge, often leading to incomplete or inaccurate data collection. Though fiscal and logistical constraints frequently beset less encumbered by terrain, manned aerial surveyss. Helicopters or fixed-wing aircraft employed for aerial surveys necessitate specialized equipment and skilled pilots, thereby incurring elevated operational costs. Furthermore, inclement weather conditions such as strong winds or fog can curtail flight operations, further complicating data acquisition endeavors. Fri, 01 Mar 2024 00:00:00 GMT http://localhost:8081/jspui/handle/123456789/20485 2024-03-01T00:00:00Z